Marketing Communications

MEDIA OBJECTIVES 257

One technique to judge the effectiveness of the media is b-coefficient analysis, developed

by Morgensztern, in which the relationship between the number of exposures and the degree

of memorisation (i.e. the percentage of the target group that remembers the ad) is analysed.

The mathematical form of the β-coefficient model is as follows:

Mn = 1 − (1 − β)n

where: Mn = memorisation after n exposures

β = medium-specific memorisation rate

Figure 8.4 illustrates the evolution of memorisation, given a β-coefficient of 12%. As the figure

illustrates, total recall increases decreasingly as a function of exposure.

The β-analysis takes into account that memorisation of a message depends on the medium

used. It is assumed that each exposure is able to make a constant percentage (β) of the con-

sumers who previously could not remember the message of a campaign actually remember

the message. Table 8.1 gives a few examples of media and their β-coefficients while Figure 8.5

shows the relation between the number of exposures and the memorisation rate for different

Table 8.1 β-coefficients for different media

Medium b-coefficient

Cinema 70%

Magazines 10%

Daily papers 10%

TV 15%

Radio 5%

Outdoor 2%

Source: Quattro Saatchi, Brussels (2003).

Figure 8.4 The β-coefficient: exposure and memorisation

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